Now the question is: Can he do it again?
And more generally: Can the Redskins do it again?
A week after coming back to beat the visiting Philadelphia Eagles on Cousins' touchdown pass to Pierre Garcon with less than 30 seconds left, the Redskins (2-2) and their still-working-to-improve QB face a more daunting task this Sunday, traveling to play at the Atlanta Falcons (4-0).
''I just need to see him continue to get better. That's all. The more (time) he sees at quarterback, the better he's going to get. It's a firm belief that repetition is king,'' Washington coach Jay Gruden said after practice Wednesday.
''And the more reps he's going to get, quarterbacks are either going to take the next step or they're not, and we want to make sure he continues taking positive steps toward getting better and doing what ... we think he can do.''
One key stat for Cousins is turnovers: When he's had any interceptions this season, the Redskins are 0-2. When he's had zero, the team's record in 2-0.
Falcons head coach Dan Quinn, who used to be Seattle's defensive coordinator, said what has stood out to him about Cousins this season is the fourth-year passer's accuracy.
Cousins is completing 68.6 percent of his throws, which is seventh among the 31 NFL quarterbacks who have thrown at least 80 passes this season.
What's Gruden been most impressed by?
''Poise and confidence, really. I think poise, mostly,'' Gruden said. ''His ability to go back and scan the field and go to his first, second and third progression, throw the ball away when he has to, overcoming a bad series or a bad game - (that) is what we are hoping to see him continue to progress with.''
Garcon sees that step forward, too.
''Confidence, communication, the role of knowing he's the quarterback. Being comfortable in the pocket, being comfortable around us, being comfortable in the huddle,'' Garcon said. ''He's definitely naturally growing. With experience, those things come.''
The game at Atlanta will be Cousins' 15th start in the pros; he is 4-9. Like with a starting pitcher in baseball, wins are not the fairest measure of an NFL quarterback's effectiveness.
With the Redskins, winning back-to-back games has not come easily the past two seasons, no matter which QB they used.
''It's definitely a test. It's going to test where guys are at,'' Pro Bowl left tackle Trent Williams said. ''It's going to test: Have we really changed? Has the complexion of this team really changed?''
Notes: WR DeSean Jackson was a limited participant in his first practice since injuring his left hamstring in the Sept. 13 season opener. ''Doesn't really hurt, I don't really have that pain anymore, but obviously I've been out for weeks, so just getting acclimated, getting that flow,'' Jackson said. ''Getting that blood moving, stuff like that.'' He said ''it's possible'' he could improve enough to play against Atlanta. ... TE Jordan Reed (concussion) and CB Chris Culliver (knee) missed practice. ... Gruden laughed off a question about whether RB Matt Jones needed to earn back trust after two fumbles in the teams' first three games. Jones got only seven carries for 11 yards in Week 4; Alfred Morris had 17 carries for 62 yards. Jones, Gruden said, ''never lost my trust. A couple of weeks ago it was, `Alfred is in my doghouse,' and he's not. It's the way it works out with the handoffs and the carries. I like both of those guys.''
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